Mating Cheek to Cheek

Humans do it. Our great ape cousins, the bonobos, do it. Now researchers have documented western gorillas mating face to face in the wild. This photograph, taken by a German research team in Nouabale-Ndoki National Park in the Republic of Congo, shows two western lowland gorillas embracing before engaging in what is politely called ventro-ventral copulation, as opposed to the front-to-back or dorso-ventral position favored by most primates. The female in the photograph, nicknamed "Leah," has a knack for being first: In 2005 the same researchers observed her using a stick to test the depth of a pool of water--the first known example of tool use by her kind. Before this photo, researchers had only seen western gorillas mating ventro-ventrally in captivity. Their population in the wild has declined by 60 percent in recent years owing to illegal hunting, habitat loss and disease, according to the Wildlife Conservation Society.